Make one cup of really strong coffee (using espresso beans if you have them)

Add 2 Tbsp chocolate powder (like girhadelli) to a half a cup of warmed milk, stir to dissolve the chocolate powder. More milk/cocoa mixture over hot coffee. Top with whip cream and drizzle with chocolate syrup. (Hersheys used to make great dark chocolate syrup in the can that was wonderful for this but now I can't find it...)

If you live near a Penzeys spices store there hot cocoa mix is great for this..

This also works great over ice in the summer! I heat the chocolate and milk beforehand and put it in the jar in the fridge for a cold one. I totally second the pp about ghiradelli choc powder...yum...may have to go make one!

I keep a mason jar in my pantry with my "chocolate mix". It's half hot chocolate, half Nesquick (to make it a little healthier!), and a little bit of powdered vanilla caramel creamer. I put a little of this and some milk in my coffee every morning!